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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
commit | ace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch) | |
tree | b2d64bc10158fdd5497876388cd68142ca374ed3 /lib/livepatch/test_klp_callbacks_busy.c | |
parent | Initial commit. (diff) | |
download | linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip |
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | lib/livepatch/test_klp_callbacks_busy.c | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/lib/livepatch/test_klp_callbacks_busy.c b/lib/livepatch/test_klp_callbacks_busy.c new file mode 100644 index 0000000000..133929e0ce --- /dev/null +++ b/lib/livepatch/test_klp_callbacks_busy.c @@ -0,0 +1,70 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (C) 2018 Joe Lawrence <joe.lawrence@redhat.com> + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/workqueue.h> +#include <linux/delay.h> + +/* load/run-time control from sysfs writer */ +static bool block_transition; +module_param(block_transition, bool, 0644); +MODULE_PARM_DESC(block_transition, "block_transition (default=false)"); + +static void busymod_work_func(struct work_struct *work); +static DECLARE_WORK(work, busymod_work_func); +static DECLARE_COMPLETION(busymod_work_started); + +static void busymod_work_func(struct work_struct *work) +{ + pr_info("%s enter\n", __func__); + complete(&busymod_work_started); + + while (READ_ONCE(block_transition)) { + /* + * Busy-wait until the sysfs writer has acknowledged a + * blocked transition and clears the flag. + */ + msleep(20); + } + + pr_info("%s exit\n", __func__); +} + +static int test_klp_callbacks_busy_init(void) +{ + pr_info("%s\n", __func__); + schedule_work(&work); + + /* + * To synchronize kernel messages, hold the init function from + * exiting until the work function's entry message has printed. + */ + wait_for_completion(&busymod_work_started); + + if (!block_transition) { + /* + * Serialize output: print all messages from the work + * function before returning from init(). + */ + flush_work(&work); + } + + return 0; +} + +static void test_klp_callbacks_busy_exit(void) +{ + WRITE_ONCE(block_transition, false); + flush_work(&work); + pr_info("%s\n", __func__); +} + +module_init(test_klp_callbacks_busy_init); +module_exit(test_klp_callbacks_busy_exit); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Joe Lawrence <joe.lawrence@redhat.com>"); +MODULE_DESCRIPTION("Livepatch test: busy target module"); |